Next Generation Biomass Gasifier

Gasification of solid fuels attracts increasing interest within the energy supply sector. Allothermal concepts typically use steam as gasification agent and require heat input from external sources. In the "classical" dual fluidized bed gasifier, heat is provided in direct contact with hot bed material particles externally heated in a combustion reactor. This type of gasification system is demonstrated in Gussing and Oberwart (Austria) and yields a high quality product gas. Thus, the gas is well suited for synthesis processes. However, a substantial improvement of fuel flexibility as well as overall efficiency of the process is necessary. In order to achieve these improvements the bubbling fluidized bed, which is used in the classical gasifier design, will be replaced by a countercurrent reactor with zones of solids accumulations in sections operated in the turbulent fluidized bed regime. Therefore, the gas-solids contact, which is important for tar reforming reactions, is increased significantly. Moreover, higher gasification rates and higher efficiencies can be expected due to the improved gas-solids interaction in the gasification section.